Dry erase marking boards are available which may be marked with dry wipe markers, also known as dry erase markers or dry erasable markers. The dry erase marking boards generally comprise a rigid substrate such as a fiber board or metal having a surface coated with a smooth, hard material such as a polymer, enamel, etc. The surface coating is one that is capable of receiving and releasably retaining a marking composition. The marking compositions typically comprise a solvent-based ink which dries to a powder after it has been applied to a surface, and the powder will adhere to the erasable surface for an extended period of time without significantly flaking or otherwise peeling away from the dry erasable writing surface. However, after the ink has dried to a powder, it may be readily wiped off from the dry erasable writing surface with a dry cloth or dry eraser. No solvent is required in the erasing, and hence, these markers are known as “dry wipe” or “dry erasable”. These terms are used interchangeably in the present specification and claims.
Dry erase marking boards have a number of advantages over previously employed chalk boards, and the use has steadily increased in recent years. Dry erase marker boards provide a high contrast dark-on-light image, and can be used in combination with various colored inks to produce readable, high contrast displays. Also, dry erase marker boards produce significantly less dust than do chalk boards. The writing surfaces generally are white in appearance and are often referred to as white boards, dry erase boards or dry erasable boards, and these terms are used interchangeably in the specification and claims.
While dry erase marker boards have a number of advantages over chalk boards, over time, the surface of dry erase marker boards often begins to degrade, and the boards tend to retain traces of the marking compositions. This problem is referred to in the industry as “ghosting”. While ghosting can be removed, to some degree, by using liquid cleaners, the problem tends to increase over time, and, eventually, the marker board must be replaced.
It has been suggested in the art that dry erase boards can be prepared from films having dry erase characteristics by adhering such films to a solid substrate such as a board with an adhesive. However, one of the difficulties of adhering the films to a solid substrate is the formation of bubbles and wrinkles in the film due to air or moisture trapped under the adhesive film as it is applied to the substrate. Another problem which is encountered is the difficulty of positioning the film with any precision due to the initial strong bond formed by the adhesive on contact with the substrate. It is desirable to be able to reposition, slide, or even remove the film after light application of pressure without destroying the film or the substrate.